addition to avoidable technical errors, early graft failure may be secondary to endothelial trauma, the use of imperfect conduit, or poor surgical judgement with regard to the adequacy of inflow or outflow.

Graftfailurewithinthefirstfewyearsofsurgeryisusuallyattributabletointimalhyperplasia. Subsequent graft failure is most frequently secondary to progression of atherosclerotic disease.

It is vital to identify a failing graft before complete occlusion to preserve the patency of the graft. Lower-extremity revascularization can be salvaged with simple interventions if lesions leading to intimal hyperplasia and hemodynamic compromise can be identified before graft thrombosis. Revision of stenotic lesions in a failing but nonoccluded graft results in superior patency when compared with revision of similar lesions in an occluded graft. It also leads to fewer amputations and subsequent revisions. Additionally, the repair of a failing graft is less costly than emergent revision of a failed graft or of amputation.13

Postoperativeduplexultrasonographydetectscorrectableabnormalitiesearly,precludes the need for angiography in many cases, and markedly improves assisted primary patency of vein bypass grafts. Recommended surveillance includes initial ABI and duplex studies at 1 week, followed by evaluations at 3, 6, 9, 12, 18, and 24 months, then annually thereafter. High-grade stenoses can be identified and corrected before thrombosis occurs. Criteriaforthediagnosisofafailinggraftincludemonophasicsignals,peaksystolicvelocity (PSV) less than 45 cm/s throughout the bypass, any PSV greater than 300 cm/s, or a PSV ratio across a stenosis of greater than 3.5.14 [Q5: C]

References

 1. Illig KA, Ouriel K. Nonoperative treatment of claudication. In: Cameron JL, ed. Current surgical therapy. 6th ed. St Louis: Mosby; 1998:767-770.

 2. Aalders GJ, van Vroonhoven TJMV. Polytetrafluoroethylene versus human umbilical vein in above-knee femoropopliteal bypass: six-year results of a randomized clinical trial. J Vasc Surg. 1992;16:816-824.

 3. Martin RS, Edwards WH, Mulherin JL, Edwards WH, Jenkins JM, Hoff SJ. Cryopreserved saphenous vein allografts for below-knee lower extremity revascularization. Ann Surg. 1994;219:664-672.

 4. AbuRahma AF, Robinson PA, Holt SM. Prospective controlled study of polytetrafluoroethylene versus saphenous vein in claudicant patients with bilateral above knee femoropopliteal bypasses. Surgery. 1999;126:594-602.

 5. Green RM, Abbott WM, Matsumoto T, et al. Prosthetic above-knee femoropopliteal bypass grafting: five-year results of a randomized trial. J Vasc Surg. 2000;31:417-425.

 6. LaSalle AJ, Brewster DC, Corson JD, Darling RC. Femoropopliteal composite bypass grafts: current status. Surgery. 1982;92:36-39.

 7. Henry M, Amor M, Ethevenot G, et al. Initial experience with the Cragg Endopro System 1 for intraluminal treatment of peripheral vascular disease. J Endovasc Surg. 1994;1:31-43.

 8. Spoelstra H, Casselman F, Lesceu O. Balloon-expandable endobypass for femoropopliteal athero-sclerotic occlusive disease. J Vasc Surg. 1996;24:647-654.

 9. Pappas PJ, Hobson RW, Meyers MG, et al. Patency of infrainguinal polyte-trafluoroethylene bypass grafts with distal interposition vein cuffs. Cardiovasc Surg. 1998;6:19-26.

10.Taylor RS, Loh A, McFarland RJ, Cox M, Chester JF. Improved technique for polytetrafluoroethylene bypass grafting: long-term results using anastomotic vein patches. Br J Surg. 1992;79:348-354.

11.Comerota AJ, Weaver FA, Hosking JD, et al. Results of a prospective, randomized trial of surgery versus thrombolysis for occluded lower extremity bypass grafts. Am J Surg. 1996;172:105-112.

12.Bandyk DF, Bergamini TM, Towne JB. Durability of vein graft revision: the outcome of secondary procedures. J Vasc Surg. 1991;13:200-210.

13.Wixon CL, Mills JL, Westerband A, Hughes JD, Ihnat DM. An economic appraisal of lower extremity bypass graft maintenance. J Vasc Surg. 2000;32:1-12.

14.Calligaro KD, Syrek JR, Dougherty MJ, et al. Selective use of duplex ultrasound to replace preoperative arteriography for failing arterial vein grafts. J Vasc Surg. 1998;27:89-95.

Enrico Ascher and Anil P. Hingorani

An 85-year-old male with a history of diabetes, hypertension, hypercholesterolemia, coronary artery bypass, and active tobacco use presented with a gangrenous right first toe. The patient stated that he had no history of trauma to the area, and complained of rest pain in the foot. The patient had been in otherwise good health since his coronary artery bypass 12 years ago. On physical examination, the patient was in no physical distress.Thepatienthadawell-healedmediansternotomyscar.Auscultationoftheheart revealed a regular rate without any murmurs. He was obese. Abdominal examination revealed no palpable masses. The patient had bilateral femoral and popliteal pulses but no pedal pulses. The patient had bilateral, well-healed scars from the greater saphenous vein harvest sites. The right gangrenous toe was dry without any evidence of infection.

Question 1

Which of the following statements regarding chronic lower-extremity ischemia are wrong?

A.  If the patient refuses any intervention, then anticoagulation alone may be helpful

B.  The contralateral asymptomatic lower extremity should also undergo angiography as there may be severe atherosclerotic disease there as well

C.  The treatment options remain unchanged if the patient presents with only rest pain, ischemic ulcer or claudication

D.  The patient cannot undergo revascularization without contrast arteriography as there are no other alternatives

The patient’s arterial duplex demonstrated moderate distal right superficial femoral artery disease. The ankle brachial indices (ABIs) and pulse volume recordings demonstrated findings consistent with moderately decreased perfusion at the calf level and severely decreased perfusion at the ankle and transmetatarsal levels. The cardiac review of systems was unremarkable, and a persantine thallium obtained 6 months ago revealed no perfusion defects. Electrocardiogram (ECG), chest X-ray and routine preoperative blood tests were

E. Ascher ( )

The Vascular Institute of New York, Brooklyn, NY, USA

normal. Venous duplex mapping revealed inadequate veins (sclerotic and too small) in the bilateral upper and lower extremities.

Question 2

Preoperative medications/lifestyle changes that should be added to the patient’s regimen to reduce his overall cardiovascular risk based upon randomized prospective data include:

A.  Aspirin B.  A statin

C.  Angiotensin-converting enzyme inhibitors D.  Tobacco cessation

E.  A beta-blocker

Percutaneous angiogram of the right lower extremity demonstrated moderate right distal superficial femoral artery stenosis with distal occlusion. The popliteal appeared to be severely diseased with occlusion of the tibioperoneal artery and proximal anterior tibial artery.Themid-anteriortibialarteryreconstitutedandrandowntothedorsalispedisartery. No other vessels appeared to be adequate.

Question 3

What type of options would you consider for this lower extremity?

A.  Below-knee amputation B.  Digital amputation

C.  Tibial bypass with expanded polytetrafluoroethylene (ePTFE) with a venous interposition or fistula

D.  Tibial bypass with cadaveric vein E.  Sympathectomy

F.  Chelation therapy

G.  Subintimal angioplasty

The patient underwent a successful bypass with ePTFE to the anterior tibial artery and did stop smoking after the procedure. The patient’s toe underwent autoamputation and the rest pain has resolved. He was followed up 2 years after the procedure with a patent bypass.

Question 4

What is the patient’s long-term prognosis in terms of mortality, graft patency, and limb salvage after successful bypass?

A.  The long-term mortality, patency, and limb salvage are about 20% and therefore are so poor that no intervention should be made.